Cardiovascular Testing Techniques

Cardiovascular Testing
Techniques
Methods of Testing
Cardiac Function
• Holter Monitors
• Non-exercise stress testing
– Dobutamine induced increases in HR
• Echocardiography
– Stress Echocardiogram
• Graded Exercise Testing
• Nuclear (thallium or technetium) chemical tests
• Coronary angiography
Relative Contraindications
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Severe hypertension
Mild-to- moderate aortic stenosis,
Hypertrophic obstructive cardiomyopathy
Frequent ectopy
Orthopedic limitations
Other conditions that may increase
relative risk
Absolute Contraindications
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Acute CHF
Acute MI
Active myocarditis
Ongoing unstable angina
Recent embolism
Dissecting aneurysm
Acute illness,
Thrombophlebitis
Moderate-to-severe aortic stenosis
EKG that cannot be interpreted
EKG Contraindications
Conditions that preclude reliable ECG interpretation:
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Left bundle branch block
Wolff-Parkinson-White
Physiological rate adaptive pacing
Left ventricular hypertrophy with ST segment changes
Extensive anterior wall infarction
Exercise testing may still provide useful information
on exercise capacity and hemodynamic responses
Left Bundle Branch Block
Wolff-Parkinson-White Syndrome
• Electrically active muscle fibers
bridge the atria and ventricles
and cause pre-excitation of the
ventricles.
• This accessory pathway is able
to conduct faster than the AV
node.
• WPW is a reentry mechanism
with an accessory pathway.
– Can be difficult to diagnose in some
children because of the higher
normal sinus rates and rapid AV
node conduction.
Wolff-Parkinson-White Syndrome
LVH with ST segment changes
Pharmacological Impact on
CV Response to Exercise
• Beta-blockers
– peak HR may be 50 to 60% less than
predicted max HR
– systolic rise of only 20 to 30 mm Hg
• Vasodilators
– restricted BP increases